Gas spring system for a height adjustable table, height adjustable table and method for operating the gas spring system

ABSTRACT

A gas spring system (3) for a height adjustable table (1) comprises a gas spring (4) having a gas spring cylinder (6) with a gas compartment (9) provided therein, a gas spring piston (7) arranged therein and a gas spring piston rod (8) joined thereto. The gas spring system (3) further comprises a gas interface (10), connected to the gas compartment (9), which at least inserts gas from outside into the gas spring system (3), a transfer cylinder (12) having a transfer piston (13), a first transfer chamber (14) and a second transfer chamber (15) separated by the transfer piston (13), and a hydraulic pump (16). The gas comportment (9) is connected to the first transfer chamber (14) and the hydraulic pump (16) is connected to the second transfer chamber (15). The hydraulic pump (16) conveys hydraulic oil and the transfer piston (13) is moved in direction towards the first transfer chamber (14) by the hydraulic oil conveyed by the hydraulic pump (16) in order to increase a pressure in the first transfer chamber (14) and in the gas comportment (9).

RELATED APPLICATION

This application claims the benefit of priority of Germany PatentApplication No. 10 2020 211 523.0 filed on Sep. 14, 2020, the contentsof which are incorporated herein by reference in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The invention relates to a gas spring system for a height adjustabletable, a height adjustable table and a method for operating the gasspring system, particularly for a table having varying loads.

Document WO 2014/183775 A1 describes an adjustable gas compressionspring, a height adjustable column having a gas compression spring, anda furniture having the height adjustable column, wherein a gascompartment of the gas spring is connected to a gas storage. The volumeof the gas storage can be varied via a piston shiftable by a translationscrew, whereby the system pressure and, therefore, the lifting force ofthe gas spring can be changed. Upon an enduring change of a load on atabletop, for example, by putting on or removing a printer or byattaching a screen wall, the lifting force of the gas spring can beadapted and an economic operation of the height adjustment can berealized again. The translation screw is driven either manually by meansof a crank or, for example, by a cordless screwdriver.

However, an adjustment of the system pressure and, therefore, of thelifting force of the gas spring via a variation of the volume of the gasstorage by means of a translation screw is elaborate and, particularlywhen using the cordless screwdriver, it is associated with an enormousamount of time if the cordless screwdriver is not immediately available.

Therefore, the object underlying the invention is to solve the aboveproblem and to provide a gas spring system, a height adjustable tableand a method for operating the gas spring system enabling a simple andquick adjustment of a force of a gas spring.

The object is achieved by a gas spring system according to claims 1, 5,9 and 12, a height adjustable table according to claim 14 as well as bya method according to claims 15 and 17. Advantageous furtherdevelopments are included in the dependent claims.

SUMMARY OF THE INVENTION

According to an aspect of the invention, a gas spring system for aheight adjustable table comprises a gas spring having a gas springcylinder with a gas compartment provided therein, a gas spring pistonarranged in the gas compartment and a gas spring piston rod joined withthe gas spring piston. Further, the gas spring system comprises a gasinterface connected to the gas compartment, wherein the gas interface isat least configured to insert gas from outside of the gas spring systeminto the gas spring system. Furthermore, the gas spring system comprisesa transfer cylinder having a transfer piston, a first transfer chamber,and a second transfer chamber, wherein the first transfer chamber andthe second transfer chamber are separated by the transfer piston and,moreover, it comprises a hydraulic pump, wherein the gas compartment ofthe gas spring is connected to the first transfer chamber, the hydraulicpump is connected to the second transfer chamber, the hydraulic pump isconfigured to convey hydraulic oil, and the transfer piston isconfigured to be moved in direction towards the first transfer chamberby the hydraulic oil conveyed by the hydraulic pump in order to increasea pressure in the first transfer chamber and the gas compartment of thegas spring.

Since an applied hydraulic all is incompressible, a volume of the firsttransfer chamber can precisely be changed by the usage of the transfercylinder and the hydraulic pump and, thus, a pressure in the gascompartment in the gas spring cylinder can be quickly and exactlyincreased in order to thus increase a gas spring force. Since the pumpenables a large conveying capacity, it is not necessary to apply acordless screwdriver for enabling a quick adjustment of the gas springforce.

Via the gas interface connected to the gas compartment, it is possibleto insert gas from outside into the gas spring system in order to, forexample, preset the pressure in the gas compartment and, therefore, thegas spring force at delivery so that, e.g., an ergonomic heightadjustment of the table upon a predefined load is possible.

In an advantageous implementation of the gas spring system, thehydraulic pump is configured to be operated by hand.

Upon an operation by hand, it's not necessary to make the efforts toprovide a tool or, e.g., a cordless screwdriver for increasing the gasspring force and, thus, e.g., the lifting force of the gas spring afteran increase of the load of the tabletop.

According to a further advantageous implementation of the gas springsystem, the gas spring system further comprises a hydraulic oil checkvalve arranged between the hydraulic pump and the second transferchamber and configured to prevent a flow of the hydraulic oil from thesecond transfer chamber towards the hydraulic pump and to enable a flowof the hydraulic oil from the hydraulic pump towards the second transferchamber.

By the provision of the hydraulic oil check valve, oil can be conveyedfrom the hydraulic pump to the second transfer chamber, however, it isprevented that an oil pressure in the second transfer chamber and,therefore, a gas pressure in the first transfer chamber and in the gascompartment of the gas spring is reduced by a leakage in the hydraulicpump. The hydraulic oil check valve can either be included in aconnection line between the hydraulic pump and the transfer cylinder orit can be integrated in the hydraulic pump.

In a further advantageous implementation of the gas spring system, thegas spring system comprises an oil reservoir and a hydraulic oilpressure drain valve, wherein the hydraulic oil pressure drain valve isconfigured to establish or separate a direct connection between thesecond transfer chamber and the oil reservoir.

By the provision of the hydraulic oil pressure drain valve, there is theoption to reduce the oil pressure in the second transfer chamber and,therefore, the gas pressure in the first transfer chamber and in the gascompartment of the gas spring for, e.g., reducing the gas spring force,e.g., when the load of the tabletop is reduced. Since the oil reservoiris provided, it is possible to collect the surplus oil from the secondtransfer chamber and, as the case may be, to return it to the secondtransfer chamber when the load on the tabletop is later increased.

According to another aspect of the invention, a gas spring systemcomprises a gas spring having a gas spring cylinder with a gascompartment provided therein, a gas spring piston arranged in the gascompartment and a gas spring piston rod joined with the gas springpiston. Further, the gas spring system comprises a gas interfaceconnected to the gas compartment of the gas spring, wherein the gasinterface is at least configured to insert gas from outside of the gasspring system, a reciprocating pump connected to the gas compartment ofthe gas spring and configured to convey gas from the atmosphere to thegas compartment of the gas spring, wherein the reciprocating pumpcomprises a drive mechanism configured to function according to theprinciple of a toggle lever system.

By applying the drive mechanism according to the principle of a togglelever system, it is possible to increase the gas pressure in the gascompartment of the gas spring by means of the reciprocating pump uponlow effort and quickly. By the principle of a toggle lever system, alarge stroke of a piston of the reciprocating pump from a posture of thereciprocating pump before a pump motion, therefore, a quick conveyanceof a gas, can be enabled upon a relatively low effort. Further, theeffort for the motion into a position of the piston of the reciprocatingpump at the end of the pump motion at a built up high pressure cannoticeably be reduced. Thus, an effective and rapid increase of thepressure in the gas compartment of the gas spring and, therefore, of theforce of the gas spring is possible. Moreover, such an implementationenables a compact structure having few components.

Also according to this aspect, it is possible to insert gas from outsideinto the gas spring system via the gas interface connected to the gascompartment in order to pre-adjust, e.g., at delivery, the pressure inthe gas compartment and, thus, the gas spring force in order to enablean ergonomic height adjustment of the table for a predefined load.

According to an advantageous implementation of the gas spring system,the reciprocating pump comprises a pump cylinder and a pump pistonhaving a pump piston rod connected to this and being movable in apredetermined direction. Further, the drive mechanism comprises a firstsupport device movable relatively to the pump cylinder in thepredetermined direction, wherein the pump piston rod is joined with thefirst support device, a second support device fixed with respect to thepump cylinder, a first lever joined in an articulated manner with thefirst support device, a second lever respectively joined in anarticulated manner with the second support device and the first leverfor forming the drive device according to the principle of a togglelever system.

By this arrangement, a design of the drive according to the principle ofa toggle lever system as simple as possible is possible.

According to a further advantageous implementation of the gas springsystem, the gas spring system further comprises a pump check valveconfigured to prevent a flow of the gas from the gas compartment of thegas spring towards the reciprocating pump and to enable a flow of thegas from the reciprocating pump towards the gas compartment of the gasspring.

By the provision of the pump check valve, the gas can be conveyed fromthe reciprocating pump towards the gas compartment of the gas spring,however, it is prevented that the gas pressure in the gas compartmentreduces due to a leakage in the reciprocating pump.

The pump check valve can either be included in a connection line betweenthe reciprocating pump and the gas spring or it can be integrated in thereciprocating pump.

In a further advantageous implementation of the gas spring system, thegas spring system further comprises a venting valve provided in a linebetween the reciprocating pump and the gas compartment of the gas springand which is configured to the exhaust gas from the gas spring system.

By the provision of the venting valve, there is the option to reduce thegas pressure in the gas compartment of the gas spring for reducing thegas spring force, e.g., when a load on the tabletop is reduced.

According to another aspect of the invention, the gas spring systemcomprises a gas spring having a gas spring cylinder with a gascompartment provided therein, a gas spring piston arranged in the gascompartment and a gas spring piston rod joined with the gas springpiston, as well as a reciprocating pump connected to the gas compartmentof the gas spring and configured to convey gas into the gas compartmentof the gas spring. The reciprocating pump comprises a first pump gascompartment connected to the gas compartment of the gas spring, a pumppiston, a second pump gas compartment separated from the first pump gascompartment by the pump piston, a pump check valve configured to preventa flow of the gas from the gas compartment towards the first pump gascompartment and to enable a flow of the gas from the first pump gascompartment towards the gas compartment, a piston check valve configuredto be movable with the pump piston and to prevent a flow of the gas fromthe first pump gas compartment to the second pump gas compartment and toenable a flow of the gas from the second pump gas compartment towardsthe first pump gas compartment, and an inlet check valve configured toprevent a flow of the gas out of the second pump gas compartment and toenable a flow of the gas into the second pump gas compartment. Further,the gas spring system comprises a second gas storage connected to theinlet check valve, a gas drain valve which is, on the one side,connected to the gas compartment of the gas spring and, on the otherside, connected to the inlet check valve and the second gas storage, anda gas interface connected to the second gas storage, wherein the gasinterface is at least configured to insert gas from outside of the gasspring system into the gas spring system.

By the connection of the second gas storage and the insert check valveof the reciprocating pump, an operating force to be applied manuallyonto the piston of the reciprocating pump is reduced and, thus, pumpingof the gas towards the gas compartment of the gas spring 4 increasingthe pressure in the gas compartment and, thus, the gas spring force, isfacilitated. Further, the quantity of the necessary pump strokes isremarkably reduced with respect to a filling out of the atmosphere.

The gas drain valve with its connections enables to reduce the pressurein the gas compartment of the gas spring for reducing the gas springforce, e.g., when the load on the tabletop is reduced, wherein, however,the gas is not exhausted into the environment but to the second gasstorage in order to be available upon a subsequent necessary increase ofthe pressure in the gas compartment of the gas spring.

Due to the provision of the pump check valve, the gas can be conveyedfrom the reciprocating pump to the gas compartment of the gas spring,however, it is prevented that the gas pressure in the gas compartmentreduces due to a leakage in the reciprocating pump. The pump check valvecan either be included in a connection line between the reciprocatingpump and the gas compartment of the gas spring or it can be integratedin the reciprocating pump.

In an advantages implementation of the gas spring system, it comprises afirst gas storage connected to the gas compartment of the gas spring.

By the first gas storage, a gas volume of the gas spring system on theside of the gas compartment of the gas spring is enlarged in order toflatten a spring characteristic of the gas spring so that the liftingforce of the gas spring across its entire adjustment range remains asconstant as possible.

According to a further advantageous implementation of the gas springsystem, it comprises a first pressure display device connected to thegas compartment of the gas spring.

By the provision of the first pressure display device, the actualfilling pressure of the gas compartment of the gas spring can bemonitored. Upon an appropriate calibration, it is also possible todirectly read off a lifting force of the gas spring.

According to a further aspect of the invention, a gas spring systemcomprises a gas spring having a gas spring cylinder with a gascompartment provided therein, a gas spring piston arranged in the gascompartment, and a gas spring piston rod joined with the gas springpiston, wherein the gas spring system further comprises a gas interfaceconnected to the gas compartment and a filling cartridge, having anunchangeable gas volume, which can be connected to the gas interface.

By this gas spring system, in particular, when the filling cartridge isfilled with a high pressure gas, the gas compartment of the gas springcan easily and rapidly be filled by connecting the filling cartridge tothe gas interface.

In an advantageous implementation of the gas spring system, it furthercomprises a connection block which can be connected, on the one side,with the gas interface and, on the other side, with the fillingcartridge, wherein the connection block comprises at least one of acut-off valve, a pressure regulator or limiter and a second pressuredisplay device.

The provision of the connection block enables a comfortable and safeoperation of the gas spring system when changing the gas spring force.

According to a further aspect of the invention, a height adjustabletable is provided with a spring system.

With such a table, it is possible to perform an adaption of the liftingforce rapidly and without large effort.

According to a further aspect of the invention, a method for operating agas spring system comprises the step: pumping the hydraulic oil by meansof the hydraulic pump into the second transfer chamber so that thetransfer piston is moved in a direction towards the first transferchamber and increases the pressure in the first transfer chamber forincreasing a force of the gas spring.

Since a utilized hydraulic oil is incompressible, by the utilization ofthe transfer cylinder and the hydraulic pump, a volume of the firsttransfer chamber can be changed precisely and, thus, a pressure in thegas compartment in the gas spring cylinder can be quickly and exactlyincreased in order to increase the pressure in the gas compartment and,thus, the gas spring force. Since the pump enables a large conveyingamount, it is not necessary to employ a cordless screwdriver in order tothe enable a rapid adjustment of the gas spring force.

In an advantageous implementation of the method, it comprises the step:opening the hydraulic oil pressure drain valve for establishing aconnection between the second transfer chamber and the oil reservoir andfor reducing an oil pressure in the second transfer chamber so that thetransfer piston is moved in a direction towards the second transferchamber and the pressure in the first transfer chamber is reduced forreducing a force of the gas spring.

By opening the hydraulic oil pressure drain valve, there is thepossibility to easily reduce the oil pressure in the second transferchamber and, thus, the gas pressure in the first transfer chamber and inthe gas compartment of the gas spring in order to reduce the gas springforce, e.g., when the load on the tabletop is reduced. Since the oilreservoir is provided, it is possible to collect the surplus oil fromthe second transfer chamber and, as the case may be, to return it to thesecond transfer chamber upon a later increase of the load on thetabletop.

According to another aspect of the invention, the method comprises thesteps: pumping gas from the second gas storage to the gas compartment ofthe gas spring for increasing a force of the gas spring, and exhaustingthe gas from the gas compartment of the gas spring to the second gasstorage by means of the gas drain valve for reducing the force of thegas spring.

By pumping the gas from the second gas storage, an operating force ontothe piston of the reciprocating pump to be applied manually is reducedand, thus, the pumping of the gas towards the gas compartment of the gasspring for increasing the pressure in the gas compartment and, thus, thegas spring force is facilitated. Further, the quantity of the necessarypump strokes is noticeably reduced compared to a filling from theatmosphere. Moreover, the pressure in the gas compartment of the gasspring can be reduced for reducing the gas spring force, e.g., when theload on the tabletop is reduced, wherein the gas is not exhausted to theenvironment but to the second gas storage in order to be available againfor a subsequent necessary increase of the pressure in the gascompartment of the gas spring.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Below, the invention is elucidated by means of embodiments referring tothe attached drawings.

In particular,

FIG. 1 shows a height adjustable table having a gas spring systemaccording to the invention;

FIG. 2 shows a schematic illustration of a first embodiment of the gasspring system;

FIG. 3 shows a schematic illustration of a second embodiment of the gasspring system;

FIG. 4 shows a schematic illustration of a third embodiment of the gasspring system; and

FIG. 5 shows a schematic illustration of a fourth embodiment of the gasspring system.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

FIG. 1 shows an adjustable table 1 having two height adjustable columns2 as table legs respectively provided with a gas spring system 3. Thegas spring systems 3 respectively comprise a gas spring 4 inside the twoheight adjustable columns 2 for adjusting a length of the heightadjustable columns 2. Further, the height adjustable table 1 comprises atabletop 5 which is height adjustable by means of the two heightadjustable columns 2.

Alternatively, the table 1 does not comprise two height adjustablecolumns 2 but either only one height adjustable column 2 or more thantwo height adjustable columns 2. Further alternatively, the gas springsystem 3 is not provided in a height adjustable table 1 but in anotherfurniture having a force assisted adjustable component. The gas springin this application is configured as a compression gas spring, however,it can alternatively also be configured as a tensile gas spring.

FIG. 2 shows a schematic illustration of a first embodiment of the gasspring system 3.

The gas spring 4 comprises a gas spring cylinder 6 and a gas springpiston 7 arranged in the gas spring cylinder 6. The gas spring piston 7is joined with a gas spring piston rod 8 and limits a gas compartment 9in the gas spring cylinder 6.

The gas spring system 3 comprises a gas interface 10 connected to thegas compartment 9 of the gas spring 4 and being at least configured toinsert gas from outside of the gas spring system 3 into the gas springsystem 3. The gas interface 10 is directly connected to the gascompartment 9 via a gas line 11. Alternatively, the gas interface 10 canalso be integrated in the gas spring 4 such that it is connected to thegas compartment 9 of the gas spring 4. In FIG. 2, the gas interface 10is illustrated as a check valve. Alternatively, it is also possiblethat, e.g., a cutoff valve is provided as the gas interface 10.

Further, the gas spring system 3 comprises a transfer cylinder 12 inorder to transfer an oil pressure to a gas pressure. The transfercylinder 12 comprises a transfer piston 13, a first transfer chamber 14and a second transfer chamber 15. The first transfer chamber 14 and thesecond transfer chamber 15 are separated by the transfer piston 13.

Moreover, the gas spring system 3 comprises a hydraulic pump 16configured to convey a hydraulic oil. The hydraulic pump 16 isconfigured to be operated by hand via a crank. Alternatively, there isthe option to operate the hydraulic pump by hand by means of a lever orby means of a motor.

The gas compartment 9 of the gas spring 4 is connected to the firsttransfer chamber 14 by means of the gas line 11. Alternatively, thetransfer cylinder 12 and the gas spring 4 can be formed integrally. Thehydraulic pump 16 is connected to the second transfer chamber 15 bymeans of an oil line 17. The transfer piston 13 is configured to bemoved by the hydraulic oil conveyed by the hydraulic pump 16 indirection towards the first transfer chamber 14 so that the transferpiston 13 transfers the pressure of the hydraulic oil into the pressureof a gas in order to increase a pressure in the first transfer chamber14 and the gas compartment 9 of the gas spring 4 in order to thus set ahigher gas spring force.

The gas spring system 3 further comprises a hydraulic oil check valve 18which is arranged in the oil line 17 between the hydraulic pump 16 andthe second transfer chamber 15. The hydraulic oil check valve 18 isconfigured to prevent a flow of the hydraulic oil from the secondtransfer chamber 15 toward the hydraulic pump 16 and to enable a flow ofthe hydraulic oil from the hydraulic pump 16 towards the second transferchamber 15. Alternatively, the hydraulic oil check valve 18 can also beintegrated either in the transfer cylinder 12 or in the hydraulic pump16, or, particularly in the case of a reliably tight hydraulic pump 16,it can be omitted.

Finally, the gas spring system 3 comprises an oil reservoir 19 and ahydraulic oil pressure drain valve 20. The oil reservoir 19 is filledwith the hydraulic oil in order to be provided for the hydraulic pump 16via the oil line 17. The hydraulic oil pressure drain valve 20 isconnected to the oil line 17 such that it bypasses the hydraulic pump 16and the hydraulic oil check valve 18. Thus, the hydraulic oil pressuredrain valve 20 is able to establish or shut off a direct connectionbetween the second transfer chamber 15 and the reservoir 19.

In this embodiment, the gas spring system 3 is illustrated in the mannerthat an own transfer cylinder 12 and an own hydraulic pump 16 isprovided for each gas spring 4. In alternative embodiments, the oilreservoir 19 and/or of the hydraulic pump 16 and/or the transfercylinder 15 are provided for several gas springs 4.

In use, the gas spring system 3 is filled with gas having a necessarypressure for an economic height adjustment, e.g., at delivery or duringinstallation of the height adjustable table 1. In a case in which anadditional load is enduringly applied onto the tabletop 5, for exampleby putting on a printer or a screen wall, the lifting force of the gasspring 4 can be adapted by pumping hydraulic oil from the oil reservoir19 into the second transfer chamber 15 by means of the hydraulic pump 16operated by hand. Since the hydraulic oil is incompressible, thetransfer piston 13 is moved in direction towards the first transferchamber 14 so that the pressure in the first transfer chamber 14 and thegas filled compartment 9 of the gas spring 4 increases in order toincrease the force of the gas spring 4. This force is transmitted to theheight adjustable column 2 via the gas spring piston 7 and the gasspring piston rod 8.

For reducing the force of the gas spring 4, the hydraulic oil pressuredrain valve 20 is opened in order to establish a connection between thesecond transfer chamber 15 and the oil reservoir 19 and to reduce an oilpressure in the second transfer chamber 15 so that the transfer piston13 is moved in direction towards the second transfer chamber 15 and thepressure in the first transfer chamber 14 and in the gas compartment 9of the gas spring 4 is reduced.

FIG. 3 shows a schematic illustration of a second embodiment of the gasspring system 3.

Analogously to the first embodiment, the gas spring system 3 comprisesthe gas spring 4 having all of its above described components and thegas interface 10.

However, instead of a hydraulic operating system, a reciprocating pump21 connected to the gas compartment 9 of the gas spring 4 and beingconfigured to convey the gas to the gas compartment 9 of the gas spring4 is provided in the second embodiment. The reciprocating pump 21comprises a drive mechanism 22 which is configured to function accordingto the principle of a toggle lever system.

Thereto, the reciprocating pump 21 comprises a pump cylinder 23 and apump piston 24 having a pump piston rod 25 joined to this and beingmovable in a reciprocating manner in a predetermined direction A. Thedrive device 22 comprises a first support device 26 movable relativelyto the pump cylinder 23 in the predetermined direction A. The pumppiston rod 25 is joined with the first support device 26. Further, thedrive device 22 comprises a second support device 27 being fixedrelatively to the pump cylinder 23. Finally, the drive device 22comprises a first lever 28 joined in an articulated manner with thefirst support device 26 and a second lever 29 respectively joined in anarticulated manner with the second support device 27 and the first lever28 in order to form the drive mechanism 22 according to the principle ofa toggle lever system. In alternative embodiments, the reciprocatingpump 21 can be formed as a multiplunger pump and/or as a double-actingpump.

The gas spring system 3 further comprises a pump check valve 30configured to prevent a flow of the gas from the gas compartment 9 ofthe gas spring 4 towards the reciprocating pump 21 and to enable a flowof the gas from the reciprocating pump 21 towards the gas compartment 9of the gas spring 4. The pump check valve 30 is provided in the gas line11 between the reciprocating pump 21 and the gas compartment 9 of thegas spring 4. Alternatively, the pump check valve 30 can also beintegrated in the reciprocating pump 21 or in the gas spring 4 or,particularly in the case of a reliably tight reciprocating pump 21, itcan be omitted.

Finally, the gas spring system 3 according to the second embodimentcomprises a venting valve 31 provided in the line 11 between thereciprocating pump 21 and the gas compartment 9 of the gas spring 4. Theventing valve 31 is configured to exhaust gas from the gas spring system3. In alternative embodiments, the venting valve can be provided on thegas spring 4 or on the reciprocating pump 21 and, particularly when thegas interface 10 is formed a stop-cock, a separate venting valve 31 canbe omitted.

The gas spring system 3 according to the second embodiment furthercomprises a first gas storage 36 and a first pressure display device 39which are connected to the gas compartment 9 of the gas spring 4. Inalternative embodiments of the gas spring system 3 either none or onlyone of the first gas storage 36 and the first pressure display device 39is provided.

In use, the gas spring system 3 is prefilled with the pressure necessaryfor an ergonomic height adjustment of the tabletop 5 via the gasinterface 10. In a case, in which an additional load is enduringlyapplied onto the tabletop 5, for example, by putting on a printer or ascreen wall, the lifting force of the gas spring 4 can be adapted bypumping air from the environment as the gas into the gas spring system 3by means of the reciprocating pump 21 operated by the toggling leversystem. For reducing the pressure, the gas can be exhausted into theenvironment via the venting valve 31.

FIG. 4 shows a schematic illustration of a third embodiment of the gasspring system 3.

As in the first and second embodiment, the gas spring system 3 accordingto the third embodiment comprises the gas spring 4 having the abovedescribed components.

The gas spring system 3 according to the third embodiment furthercomprises a reciprocating pump 21′ connected to the gas compartment 9 ofthe gas spring 4 and configured to convey gas to the gas compartment 9of the gas spring 4. Thereto, the reciprocating pump 21′ comprises afirst pump gas compartment 32 connected to the gas compartment 9 of thegas spring 4, a pump piston 24′ and a second pump gas compartment 33which is separated from the first pump gas compartment 32 by the pumppiston 24′. Further, the reciprocating pump 21′ comprises a pump checkvalve 30′ configured to prevent a flow of the gas from the gascompartment 9 of the gas spring 4 towards the first pump gas compartment32 and to enable a flow of the gas from the first pump gas compartment32 toward the gas compartment 9 of the gas spring 4. Except from that,the reciprocating pump 21′ comprises a piston check valve 34 configuredto be movable with the pump piston 24′ and to prevent a flow of the gasfrom the first pump gas compartment 32 to the second pump gascompartment 33 and to enable a flow of the gas from the second pump gascompartment 33 towards the first pump gas compartment 32. Finally, thereciprocating pump 21′ comprises an inlet check valve 35 configured toprevent a flow of the gas out of the second pump gas compartment 33 andto enable a flow of the gas into the second pump gas compartment 33.

In the third embodiment, the gas spring system 3 comprises a second gasstorage 38 which is connected to the inlet check valve 35, a gas drainvalve 37 which is, on the one side, connected to the gas compartment 9of the gas spring 4 and, on the other side, to the inlet check valve 35and the second gas storage 38, and a gas interface 10′ connected to thesecond gas storage 38, wherein the gas interface 10′ is at leastconfigured to insert gas from outside of the gas spring system 3 intothe gas spring system 3.

The gas spring system 3 according to the third embodiment further alsocomprises the first gas storage 36 and the first pressure display device39 which are connected to the gas compartment 9 of the gas spring 4. Inalternative embodiments of the gas spring system 3, either none or onlyone of the first gas storage 36 and the first pressure display device 39is provided.

The reciprocating pump 21′ of the third embodiment of the gas springsystem 3 is operated by means of the drive device according to theprinciple of a toggle lever system. Alternatively, a pump piston rod 25′can also be directly operated, e.g., by hand. In alternativeembodiments, the reciprocating pump 21′ can be designed as amultiplunger pump and/or as a double-acting pump. The reciprocating pump21′ of the third embodiment of the gas spring system 3 can also beemployed as an alternative embodiment of the reciprocating pump 21 ofthe second embodiment of the gas spring system 3.

In use, the gas spring system 3 is prefilled with the pressure necessaryfor an ergonomic height adjustment of the tabletop 5 via the gasinterface 10′. In a case in which an additional load onto the tabletop 5is enduringly applied, e.g., by putting on a printer or a screen wall,the lifting force of the gas spring 4 can be increased by pumping gasout of the second storage 38 to the gas compartment 9 of the gas spring4 by means of the reciprocating pump 21′. For reducing pressure and,thus, for reducing the force of the gas spring, the gas can be exhaustedback into the second storage 38 via the gas drain valve 37.

FIG. 5 shows a schematic illustration of a fourth embodiment of the gasspring system 3.

The gas spring system 3 according to the fourth embodiment distinguishesfrom the gas spring systems 3 according to the first to third embodimentin that that no pump for increasing the pressure in the gas compartment9 of the gas spring 4 but a filling cartridge 40 is provided. Thefilling cartridge 40 can be connected to the gas interface 10,nevertheless, it also can be detached. The filling cartridge 40 has afixed, in particular, cylindrical shape and, thus, an unchangeable gasvolume and is filled with air, nitrogen or carbon dioxide with a fillingpressure of up to 200 bar. Optionally, the filling cartridge 40 isprovided with a manometer. In the embodiment shown in FIG. 5, the gasspring system 3 further comprises a connection block 41 which can beconnected, on the one side, with the gas interface 10 and, on the otherside, with the filling cartridge 40. Thus, the filling cartridge 40 canbe connected to the gas compartment 9 of the gas spring 4 via theconnection block 41. The connection block 41 is provided with a cut-offvalve 42, a pressure regulator or limiter 43 and a second pressuredisplay device 44. In an alternative embodiment, the gas spring system 3is not provided with the connection block 41 and the filling cartridge40 is directly connected to the gas interface. Further, the connectionblock 41 comprises a further gas interface 10″ which is, formed as acheck valve, connectable to the filling cartridge 40. In furtheralternative embodiments, the cutoff valve 42 and/or the pressureregulator or limiter 43 and/or the second pressure display device 44 arenot provided. Moreover, in further alternative embodiments, theconnection block 41 is either integrated in the filling cartridge 40 orin the gas spring 4.

In use, the filling cartridge 40, as the case may be, via the connectionblock 41, is connected to the gas interface 10 and, thereby, eitherautomatically or after opening of the cutoff valve 42, the gas includedin the filling cartridge 40 at high pressure is guided into the gascompartment 9 of the gas spring 4 so that the pressure in the gascompartment 9 of the gas spring 4 increases to an appropriate value.

If it is necessary to reduce the pressure in the gas compartment 9 ofthe gas spring 4 since, for example, the load on the tabletop 5 hasdecreased, the pressure is reduced by means of the pressure regulator orlimiter 43 or, if the connection block is not provided, at the gasinterface 10 by means of an auxiliary tool.

All features illustrated in the description, the subsequent claims, andthe drawings can be solitarily as well as in an arbitrary combinationrelevant for the invention.

What is claimed is:
 1. Gas spring system (3) for a height adjustabletable (1) comprising a gas spring (4) having a gas spring cylinder (6)with a gas compartment (9) provided therein, a gas spring piston (7)arranged in the gas compartment (9), and a gas spring piston rod (8)joined with the gas spring piston (7), characterized in that the gasspring system (3) further comprises: a gas interface (10) connected tothe gas compartment (9), wherein the gas interface (10) is at leastconfigured to insert gas from outside of the gas spring system (3) intothe gas spring system (3), a transfer cylinder (12) having an transferpiston (13), a first transfer chamber, (14) and a second transferchamber (15), wherein the first transfer chamber (14) and the secondtransfer chamber (15) are separated by the transfer piston (13), and ahydraulic pump (16), wherein the gas compartment (9) of the gas spring(4) is connected to the first transfer chamber (14), the hydraulic pump(16) is connected to the second transfer chamber (15), the hydraulicpump (16) is configured to convey hydraulic oil, and the transfer piston(13) is configured to be moved by the hydraulic oil conveyed by thehydraulic pump (16) in direction towards the first transfer chamber (14)in order to increase a pressure in the first transfer chamber (14) andthe gas compartment (9) of the gas spring (4).
 2. Gas spring system (3)according to claim 1, wherein the hydraulic pump (16) is configured tobe operated by hand.
 3. Gas spring system (3) according to claim 1,wherein the gas spring system (3) further comprises a hydraulic oilcheck valve (18) arranged between the hydraulic pump (16) and the secondtransfer chamber (15) and configured to prevent a flow of the hydraulicoil from the second transfer chamber (15) towards the hydraulic pump(16) and to enable a flow of the hydraulic oil from the hydraulic pump(16) towards the second transfer chamber (15).
 4. Gas spring system (3)according to claim 1, wherein the gas spring system (3) comprises an oilreservoir (19) and a hydraulic oil pressure drain valve (20), whereinthe hydraulic oil pressure drain valve (20) is configured to establishor shut off a direct connection between the second transfer chamber (15)and the oil reservoir (19).
 5. Gas spring system (3) comprising a gasspring (4) having a gas spring cylinder (6) with a gas compartment (9)provided therein, a gas spring piston (7) arranged in the gascompartment (9), and a gas spring piston rod (8) joined with the gasspring piston (7), characterized in that the gas spring system (3)further comprises: a gas interface (10) connected to the gas compartment(9) of the gas spring (4), wherein the gas interface (10) is at leastconfigured to insert gas from outside of the gas spring system (3) intothe gas spring system (3), a reciprocating pump (21) connected to thegas compartment (9) of the gas spring (4) and which is adapted to conveygas towards the gas compartment (9) of the gas spring (4), wherein thereciprocating pump (21) comprises a drive mechanism (22) configured tofunction according to the principle of a toggle lever system.
 6. Gasspring system (3) according to claim 5, wherein the reciprocating pump(21) comprises a pump cylinder (23) and a pump piston (24) with a pumppiston rod (25) connected with this and movable in a predetermineddirection, and the drive mechanism (22) comprises: a first supportdevice (26) movable in the predetermined direction relatively to thepump cylinder (23), wherein the pump piston rod (25) is joined with thefirst support device (26), a second support device (27) fixed relativelyto the pump cylinder (23), a first lever (28) joined in an articulatedmanner with the first support device (26), and a second lever (29)joined in an articulated manner respectively with the second supportdevice (27) and the first lever (28) in order to form the drivemechanism (22) according to the principle of a toggle lever system. 7.Gas spring system (3) according to claim 5, wherein the gas springsystem (3) further comprises a pump check valve (30) configured toprevent a flow of the gas from the gas compartment (9) of the gas spring(4) towards the reciprocating pump (21) and to enable a flow of the gasfrom the reciprocating pump (21) towards the gas compartment (9) of thegas spring (4).
 8. Gas spring system (3) according to claim 5, whereinthe gas spring system (3) further comprises a venting valve (31)provided between the reciprocating pump (21) and the gas compartment (9)of the gas spring (4) and configured to the exhaust gas out of the gasspring system (3).
 9. Gas spring system (3) comprising a gas spring (4)having a gas spring cylinder (6) with a gas compartment (9) providedtherein, a gas spring piston (7) arranged in the gas compartment (9),and a gas spring piston rod (8) joined with the gas spring piston (7),wherein the gas spring system (3) further comprises: a reciprocatingpump (21′) connected to the gas compartment (9) of the gas spring (4)and configured to convey gas to the gas compartment (9) of the gasspring (4), characterized in that the reciprocating pump (21′)comprises: a first pump gas compartment (32) connected to the gascompartment (9) of the gas spring (4), a pump piston (24′), a secondpump gas compartment (33) separated from the first pump gas compartment(32) by the pump piston (24′), a pump check valve (30′) configured toprevent a flow of the gas from the gas compartment (9) of the gas spring(4) towards the first pump gas compartment (32) and to enable a flow ofthe gas from the first pump gas compartment (32) towards the gascompartment (9) of the gas spring (4), a piston check valve (34)configured to be movable with the pump piston (24′) and to prevent aflow of the gas from the first pump gas compartment (32) towards thesecond pump gas compartment (33) and to enable a flow of the gas fromthe second pump gas compartment (33) towards the first pump gascompartment (32), an inlet check valve (35) configured to prevent a flowof the gas out of the second pump gas comportment (33) and to enable aflow of the gas into the second pump gas compartment (33), wherein thegas spring system (3) further comprises: a second gas storage (38)connected to the insert check valve (35), a gas drain valve (37)connected, on the one side, with the gas compartment (9) of the gasspring (4) and, on the other side, with the insert check valve (35) andthe second gas storage (38), and a gas interface (10′) connected to thesecond gas storage (38), wherein the gas interface (10′) is at leastconfigured to insert gas from outside of the gas spring system (3) intothe gas spring system (3).
 10. Gas spring system (3) according to claim5, wherein the gas spring system (3) comprises a first gas storage (36)connected to the gas compartment (9) of the gas spring (4).
 11. Gasspring system (3) according to claim 5, wherein the gas spring system(3) comprises a first pressure display device (39) connected to the gascompartment (9) of the gas spring (4).
 12. Gas spring system (3)comprising a gas spring (4) having a gas spring cylinder (6) with a gascompartment (9) provided therein, a gas spring piston (7) provided inthe gas compartment (9), and a gas spring piston rod (8) joined with thegas spring piston (7), wherein the gas spring system (3) furthercomprises: a gas interface (10) connected to the gas compartment (9),and a filling cartridge (40), having an unchangeable gas volume,connectable to the gas interface (10).
 13. Gas spring system (3)according to claim 12, wherein the gas spring system (3) furthercomprises a connection block (41) connectable, on the one side, with thegas interface (10) and, on the other side, with the filling cartridge(40), wherein the connection block (41) comprises at least one of acutoff valve (42), a pressure regulator or a limiter (43) and a secondpressure display device (44).
 14. Height adjustable table (1) having agas spring system (3) according to claim
 1. 15. Method for operating agas spring system (3) according to claim 1 having the step: pumping thehydraulic oil by means of the hydraulic pump (16) into the secondtransfer chamber (15) so that the transfer piston (13) is moved indirection towards the first transfer chamber (14) and increases thepressure in the first transfer chamber (14) in order to increase a forceof the gas spring (4).
 16. Method according to claim 15, having thestep: opening a hydraulic oil pressure drain valve (20) in order toestablish a connection between a second transfer chamber (15) and an oilreservoir (19) and to reduce an oil pressure in the second transferchamber (15) so that the transfer piston (13) is moved in directiontowards the second transfer chamber (15) and the pressure in the firsttransfer chamber (14) is reduced in order to reduce a force of the gasspring (4).
 17. Method for operating a gas spring system (3) accordingto claim 9, having the steps: pumping gas from the second gas storage(38) to the gas compartment (9) of the gas spring (4) for increasing aforce of the gas spring (4); and exhausting the gas out of the gascompartment (9) of the gas spring (4) by means of the gas drain valve(37) to the second gas storage (38) for reducing the force of the gasspring (4).